/*
 * Copyright 2002-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.jca.cci.core;

import java.sql.SQLException;

import javax.resource.ResourceException;
import javax.resource.cci.Connection;
import javax.resource.cci.ConnectionFactory;

import org.springframework.dao.DataAccessException;
import org.springframework.lang.Nullable;

/**
 * Generic callback interface for code that operates on a CCI Connection.
 * Allows to execute any number of operations on a single Connection,
 * using any type and number of Interaction.
 *
 * <p>This is particularly useful for delegating to existing data access code
 * that expects a Connection to work on and throws ResourceException. For newly
 * written code, it is strongly recommended to use CciTemplate's more specific
 * {@code execute} variants.
 *
 * @author Thierry Templier
 * @author Juergen Hoeller
 * @see CciTemplate#execute(ConnectionCallback)
 * @see CciTemplate#execute(javax.resource.cci.InteractionSpec, javax.resource.cci.Record)
 * @see CciTemplate#execute(javax.resource.cci.InteractionSpec, RecordCreator, RecordExtractor)
 * @since 1.2
 */
@FunctionalInterface
public interface ConnectionCallback<T> {

    /**
     * Gets called by {@code CciTemplate.execute} with an active CCI Connection.
     * Does not need to care about activating or closing the Connection, or handling
     * transactions.
     * <p>If called without a thread-bound CCI transaction (initiated by
     * CciLocalTransactionManager), the code will simply get executed on the CCI
     * Connection with its transactional semantics. If CciTemplate is configured
     * to use a JTA-aware ConnectionFactory, the CCI Connection and thus the callback
     * code will be transactional if a JTA transaction is active.
     * <p>Allows for returning a result object created within the callback, i.e.
     * a domain object or a collection of domain objects. Note that there's special
     * support for single step actions: see the {@code CciTemplate.execute}
     * variants. A thrown RuntimeException is treated as application exception:
     * it gets propagated to the caller of the template.
     *
     * @param connection        active CCI Connection
     * @param connectionFactory the CCI ConnectionFactory that the Connection was
     *                          created with (gives access to RecordFactory and ResourceAdapterMetaData)
     * @return a result object, or {@code null} if none
     * @throws ResourceException   if thrown by a CCI method, to be auto-converted
     *                             to a DataAccessException
     * @throws SQLException        if thrown by a ResultSet method, to be auto-converted
     *                             to a DataAccessException
     * @throws DataAccessException in case of custom exceptions
     * @see javax.resource.cci.ConnectionFactory#getRecordFactory()
     * @see javax.resource.cci.ConnectionFactory#getMetaData()
     * @see CciTemplate#execute(javax.resource.cci.InteractionSpec, RecordCreator, RecordExtractor)
     */
    @Nullable
    T doInConnection(Connection connection, ConnectionFactory connectionFactory)
            throws ResourceException, SQLException, DataAccessException;

}
